1. Chaim Sheba Medical Center, Tel Hashomer, Israel;
2. First Teaching Hospital, Beijing Medical University, Beijing, China; and
3. Medical College of Wisconsin Dysphagia Institute, Division of Gastroenterology and Hepatology, Departments of Medicine, Radiology, and Otolaryngology, Medical College of Wisconsin, and Zablocki Department of Veterans Affairs Medical Center, Milwaukee, Wisconsin 53226